Devices and methods for a contact lens with an outward facing light source

ABSTRACT

A body-mountable device can include a transparent material and a substrate at least partially embedded in the transparent material. The transparent material can have a mounting surface and a surface opposite the mounting surface. A light source can be disposed on the substrate and configured to emit light through the surface opposite the mounting surface. The light source can be controlled by circuitry disposed on the substrate. The circuitry can be configured to receive modulation instructions and modulate the light emitted by the light source based on the modulation instructions.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 13/931,394, filed Jun. 28, 2013, which application isincorporated herein by reference.

BACKGROUND

Unless otherwise indicated herein, the materials described in thissection are not prior art to the claims in this application and are notadmitted to be prior art by inclusion in this section.

A contact lens device can include a sensor for measuring an analyte,such as glucose, in a tear film. The sensor can be an electrochemicalsensor that includes a working electrode and a counter and/or referenceelectrode. An electrochemical reaction involving the analyte cantransfer electrons to or from the working electrode so as to generate acurrent related to the concentration of the analyte. In some instances,a reagent can be located proximate to the working electrode tofacilitate a selective, electrochemical reaction with the analyte.

A contact lens device can also communicate sensor readings to anexternal reader. For example, the contact lens can include an antennathat is configured to receive radio frequency radiation from theexternal reader and produce a backscatter signal based on a sensorreading.

SUMMARY

In one example, a body-mountable device is provided that comprises atransparent material having a mounting surface and a surface oppositethe mounting surface. The device also comprises a substrate at leastpartially embedded in the transparent material. The device alsocomprises a light source disposed on the substrate and at leastpartially embedded in the transparent material. The light source can beconfigured to emit light through the surface opposite the mountingsurface. The device also comprises circuitry disposed on the substrate.The circuitry can be configured to receive modulation instructions andmodulate, based on the modulation instructions, the light emitted by thelight source to provide modulated light. The modulated light can beindicative of a human-discernible or machine-readable message from thebody-mountable device

In another example, a method performed by a body-mountable device isprovided. The method comprises receiving modulation instructions in thebody-mountable device. The body-mountable device includes a transparentmaterial. The transparent material can have a mounting surface and asurface opposite the mounting surface. The body-mountable device furtherincludes a substrate at least partially embedded in the transparentmaterial. The body-mountable device can also include a light sourcedisposed on the substrate. The method further comprises modulating,based on the modulation instructions, light emitted by the light sourceto provide modulated light. The method further comprises emitting themodulated light through the surface opposite the mounting surface. Themodulated light can be indicative of a human-discernible ormachine-readable message from the body-mountable device.

In another example, a method performed by a reader device is provided.The method comprises receiving an incident signal transmitted by abody-mountable device. The body-mountable device includes a transparentmaterial. The transparent material can have a mounting surface and asurface opposite the mounting surface. The body-mountable device furtherincludes a substrate at least partially embedded in the transparentmaterial. The body-mountable device can also include a light sourcedisposed on the substrate. The incident signal comprises light emittedby the light source and transmitted through the surface opposite themounting surface. The method further comprises determining, based on theincident signal, a message from the body-mountable device.

These as well as other aspects, advantages, and alternatives, willbecome apparent to those of ordinary skill in the art by reading thefollowing detailed description, with reference where appropriate to theaccompanying figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram of an example system 100 that includes abody-mountable device in wireless communication with an external reader.

FIG. 2A is a bottom view of an example eye-mountable device 210.

FIG. 2B is a side view of the example eye-mountable device shown in FIG.2A.

FIG. 2C is a side cross-section view of the example eye-mountable deviceshown in FIGS. 2A and 2B while mounted to a corneal surface of an eye.

FIG. 2D is a close-in side cross-section view enhanced to show thesubstrate embedded in the transparent material, the light source, andthe emitted light in the example eye-mountable device when mounted asshown in FIG. 2C.

FIG. 3 is a block diagram of an example method 300 for operating abody-mountable device, in accordance with at least some embodimentsdescribed herein.

FIG. 4 is a block diagram of an example method 400 for operating abody-mountable device via an antenna, in accordance with at least someembodiments described herein.

FIG. 5A is a block diagram of an example system 500 with aneye-mountable device that includes an outward facing light source and isoperated by an external reader.

FIG. 5B is a block diagram of the eye-mountable device 530 described inconnection with FIG. 5A.

FIG. 6A is a top view of an example eye-mountable device 610.

FIG. 6B is a side view of the example eye-mountable device shown in FIG.6A.

FIG. 7A is a block diagram of an example system 700 with aneye-mountable device and an external reader that are communicating viaemitted light by the eye-mountable device and incident light from theexternal reader.

FIG. 7B is a block diagram of the eye-mountable device 730 described inconnection with FIG. 7A.

FIG. 8 is a block diagram of an example method 800 for operating anexternal reader to receive an incident signal transmitted by abody-mountable device, in accordance with at least some embodimentsdescribed herein.

FIG. 9 is a block diagram of an example method 900 for operating anexternal reader to communicate, via light, with a body-mountable device,in accordance with at least some embodiments described herein.

FIG. 10 depicts an example computer-readable medium configured accordingto at least some embodiments described herein.

DETAILED DESCRIPTION

The following detailed description describes various features andfunctions of the disclosed systems and methods with reference to theaccompanying figures. In the figures, similar symbols identify similarcomponents, unless context dictates otherwise. The illustrative system,device and method embodiments described herein are not meant to belimiting. It may be readily understood by those skilled in the art thatcertain aspects of the disclosed systems, devices and methods can bearranged and combined in a wide variety of different configurations, allof which are contemplated herein.

An electronic device may be utilized to communicate information to otherdevices or people. The electronic device could be a body-mountabledevice. In an example embodiment, the body-mountable device is aneye-mountable device that can be mounted to an eye. In other examples,the body-mountable device could be mounted to a tooth, skin, or otherbody part. To communicate information, the body-mountable device mayinclude a light source and circuitry to operate the light source. Thecircuitry and light source may be situated on a substrate embedded in abiocompatible material that includes a mounting surface, which may beused to mount the body-mountable device to an eye or other body part,and a surface opposite the mounting surface. The light source may beconfigured to emit light through the surface opposite the mountingsurface, so that the light is emitted in a direction away from the eyeor other body part on which the body-mountable device may be mounted.

The biocompatible material could be a transparent material. For example,the light source may be arranged to emit light through the transparentmaterial so that the light is visible to an external device or to aperson viewing the body-mountable device. Alternatively, thebiocompatible material could be a non-transparent material or couldinclude a transparent portion and a non-transparent portion. Forexample, the light source may be arranged so as to emit light through atransparent portion of the biocompatible material.

In some examples, the body-mountable device is an eye-mountable device,and the biocompatible material is a transparent material in the form ofa round lens with a concave surface, which can be removably mounted on acorneal surface of an eye, and a convex surface, which faces outward,away from the eye, when the concave surface is mounted on the cornealsurface. In this example, the substrate may be embedded near theperiphery of the transparent material to avoid interference withincident light received closer to the central region of the eye. In thisexample, the light source can be arranged on the substrate to faceoutward, away from the corneal surface, so as to emit light through theconvex surface and away from the eye.

In some examples, the light source is entirely embedded within thetransparent material. In some examples, the circuitry may be configuredto cause the light source to emit modulated light that indicates amessage from the body-mountable device. For example, the body-mountabledevice may include a sensor that can obtain a reading related to ananalyte concentration (e.g., a glucose concentration), temperature, orother parameter, and the modulated light may be indicative of thereading obtained by the sensor.

The body-mountable device can be powered via radiated energy harvestedat the body-mountable device. Power can be provided by light energizingphotovoltaic cells included in the body-mountable device. Additionallyor alternatively, power can be provided by radio frequency energyharvested from an antenna included in the body-mountable device. Arectifier and/or regulator can be incorporated in the circuitry togenerate a stable DC voltage to power the body-mountable device from theharvested energy. The antenna can be arranged as a loop of conductivematerial with leads connected to the circuitry. In some embodiments,such a loop antenna can also wirelessly communicate between thebody-mountable device and an external reader by modifying the impedanceof the loop antenna so as to modify radiation from the antenna.

The light emitted by the light source may be modulated by the circuitryby modifying an aspect of the light. For example, color, brightness,intensity or duration of the light emitted by the light source may bemodulated such that the modulated light is indicative of a message. Forexample, the modulated light may include a series of light pulses thatare indicative of a reading of the sensor. In another example, the colorof the modulated light may indicate a status of the body-mountabledevice or a status of components included in the body-mountable device.

Within examples described herein, the body-mountable device may alsoinclude a photodetector configured to receive an incident light signal.The received modulation instructions can be based on the incident lightsignal. For example, the external reader may comprise a computingdevice. The computing device may emit the incident light signal torequest information from the body-mountable device. For example, theincident light signal may indicate that the body-mountable devicecommunicate the reading of the sensor. The body-mountable device may beconfigured to modulate light emitted by the light source to indicate thereading of the sensor. In some examples, the reader can include a readerphotodetector to receive the modulated light and determine a message(e.g., the reading of the sensor) from the body-mountable device.

Some embodiments of the present disclosure therefore provide systems andmethods for intermittently communicating information by modulating thelight emitted by the light source. Such an intermittent scheme mayreduce total power consumption, because the circuitry and the lightsource are only powered when the communication is necessary.

In some embodiments, the external reader may be configured to provideradio frequency radiation that may be harvested to power thebody-mountable device. In some examples, the external reader may beconfigured to provide light that the photovoltaic cells are configuredto harvest power from. Additionally or alternatively, the photovoltaiccells may harvest power from ambient light surrounding thebody-mountable device.

FIG. 1 is a block diagram of an example system 100 that includes abody-mountable device 110 in wireless communication with an externalreader 190. The exposed regions of the body-mountable device 110 can bemade of a transparent material 120 formed to be mounted to a body. Insome examples, the transparent material 120 can be contact-mounted tothe body. In other examples, the transparent material 120 can beembedded in the body (e.g., surgically embedded, etc.). The transparentmaterial 120 can have a mounting surface and a surface opposite themounting surface. A substrate 130 is embedded in the transparentmaterial 120 to provide a mounting surface for a power supply 140,circuitry 150, communication electronics 170, and light source 176. Insome embodiments, substrate 130 further comprises a sensor 178 alsomounted on the substrate 130. The power supply 140 supplies operatingvoltages to the circuitry 150. The circuitry 150 provides power andcontrols the communication electronics 170 and light source 176. Thelight source 176 is operated by circuitry 150 to provide modulatedlight. The communication electronics 170 are operated by circuitry 150to communicate information to and/or from the body-mountable device 110.In some embodiments, the antenna 174 is operated by circuitry 150 tocommunicate the information to and/or from the body-mountable device110. Additionally or alternatively, the photodetector 172 and the lightsource 176 can be operated by the circuitry 150 to communicate theinformation to and/or from the body-mountable device 110. In someembodiments, the sensor 178 receives power and is also operated bycircuitry 150 to provide a reading that may be communicated to and/orfrom the body-mountable device 110.

In some examples where the body-mountable device 110 is an eye-mountabledevice configured to be contact-mounted to an eye, to facilitatecontact-mounting, the transparent material 120 can have a concavesurface configured to adhere (“mount”) to a moistened corneal surface(e.g., by capillary forces with a tear film coating the cornealsurface). Additionally or alternatively, the body-mountable device 110can be adhered by a vacuum force between the corneal surface and thetransparent material 120 due to a concave curvature of the mountingsurface of the body-mountable device 110. In this example, while mountedwith the concave surface against the eye, the outward-facing surface ofthe transparent material 120 can have a convex curvature that is formedto not interfere with eye-lid motion while the body-mountable device 110is mounted to the eye. For example, the transparent material 120 can bea curved polymeric disk shaped similarly to a contact lens.

In some examples, the transparent material 120 can include one or morebiocompatible materials. For example, biocompatible materials employedfor use in contact lenses or other ophthalmic applications involvingdirect contact with a body can be used. The transparent material 120 canoptionally be formed in part from such biocompatible materials or caninclude an outer coating with such biocompatible materials. Thetransparent material 120 can optionally include materials configured tomoisturize a surface of the body, such as hydrogels and the like. Insome embodiments where the body-mountable device is an eye-mountabledevice, the transparent material 120 can be shaped to provide apredetermined, vision-correcting optical power, such as can be providedby a contact lens.

The substrate 130 includes one or more surfaces suitable for mountingthe power supply 140, circuitry 150, communication electronics 170, andlight source 176. In some embodiments, the one or more surfaces are alsosuitable for mounting sensor 178. The substrate 130 can be employed bothas a mounting platform for chip-based circuitry (e.g., by flip-chipmounting to connection pads) and/or as a platform for patterningconductive materials (e.g., gold, platinum, palladium, titanium, copper,aluminum, silver, metals, other conductive materials, combinations ofthese, etc.) to create electrodes, interconnects, connection pads,antennae, etc. In some embodiments, through hole pads may be patternedand/or drilled on to the substrate 130 to allow connections betweencomponents on more than one side of the substrate 130. For example, somecomponents like circuitry 150 and communication electronics 170 may bedisposed on one side of the substrate 130 and other components like thelight source 176 may be disposed on another side of the substrate 130.In some embodiments, the substrate 130 may be a multilayer substrate(e.g., printed circuit board) that allows connections between componentsincluded in the body-mountable device 110 in several layers betweenmultiple sides of the substrate 130. In some embodiments, substantiallytransparent conductive materials (e.g., indium tin oxide) can bepatterned on the substrate 130 to form circuitry 150, electrodes, etc.For example, the antenna 174 can be formed by forming a pattern of goldor another conductive material on the substrate 130 by deposition,photolithography, electroplating, etc. Similarly, interconnects 162,164, 166 between the circuitry 150 and the photodetector 172, antenna174, and light source 176, respectively, can be formed by depositingsuitable patterns of conductive materials on the substrate 130. In someembodiments, interconnects 168 may be similarly formed to connectcircuitry 150 with sensor 178.

A combination of microfabrication techniques including, withoutlimitation, the use of photoresists, masks, deposition techniques,and/or plating techniques can be employed to pattern materials on thesubstrate 130. In some examples, the substrate 130 can be a rigidmaterial, such as polyethylene terephthalate (“PET”) or a flexiblematerial, such as polyimide or organic materials configured tostructurally support the circuitry 150 and/or chip-based electronicswithin the transparent material 120. The body-mountable device 110 canalternatively be arranged with a group of unconnected substrates ratherthan a single substrate. For example, the circuitry 150 can be mountedto one substrate, while the light source 172 is mounted to anothersubstrate and the two can be electrically connected via interconnects162.

In some embodiments where the body-mountable device 110 is aneye-mountable device, the substrate 130 (and other components includedin the body-mountable device 110) can be positioned away from the centerof the body-mountable device 110 and thereby avoid interference withlight transmission to the central, light-sensitive region of the eye(e.g., avoid field of view of the eye). For example, where thebody-mountable device 110 is shaped as a concave-curved disk, thesubstrate 130 can be embedded around the periphery (e.g., near the outercircumference) of the disk. In some embodiments, however, the substrate130 can be positioned in or near the central region of thebody-mountable device 110. For example, the body-mountable device 110can be a tooth-mounted device, and the substrate 130 can be embedded inany location inside the transparent material 120. Additionally oralternatively, the substrate 130 (and other components included in theeye-mountable device 110) can be substantially transparent to incomingvisible light to mitigate interference with light transmission to thebody. For example, the body-mountable device 110 can be a skin-mounteddevice, and the substrate 130 can be substantially transparent to allowsunlight to reach the skin.

In some embodiments, the substrate 130 can be shaped as a flattened ringwith a radial width dimension sufficient to provide a mounting platformfor embedded electronics components. The substrate 130 can have athickness sufficiently small to allow the substrate 130 to be embeddedin the transparent material 120 without influencing a shape of thebody-mountable device 110. The substrate 130 can have a thicknesssufficiently large to provide structural stability suitable forsupporting electronics mounted thereon. For example, substrate 130 canbe shaped as a ring with a diameter of about 10 millimeters, a radialwidth of about 1 millimeter (e.g., an outer radius 1 millimeter largerthan an inner radius), and a thickness of about 50 micrometers. However,the diameter, radial width and thickness values are provided forexplanatory purposes only. In some embodiments, the dimensions of thesubstrate 130 can be selected according to the size and/or shape of thebody-mountable device 110. The substrate 130 can optionally be alignedwith a curvature of a surface of the body-mountable device 110.

The power supply 140 is configured to harvest energy to power thecircuitry 150, communication electronics 170, and light source 176. Insome embodiments, power supply 140 may also be configured to powersensor 178. For example, a radio-frequency energy-harvesting antenna 142can capture energy from incident radio radiation. Additionally oralternatively, photovoltaic cell(s) 144 (e.g., solar cells) can captureenergy from incoming ultraviolet, infrared, visible, and/or invisibleradiation. In some embodiments, the incident radio radiation and/orincoming radiation may be ambient radiation in surroundings of thebody-mountable device 110. Additionally or alternatively, the incidentradio radiation and/or incoming radiation may be from the externalreader 190. Furthermore, an inertial power scavenging system can beincluded to capture energy from ambient vibrations. The energyharvesting antenna 142 can optionally be a dual-purpose antenna that isalso used to communicate information from/to the external reader 190.That is, the functions of the antenna 174 and the energy harvestingantenna 142 can be accomplished with a same physical antenna.

In one example, a rectifier/regulator 146 can be used to conditioncaptured energy to a stable DC supply voltage 148 that is supplied tocircuitry 150. For example, the energy harvesting antenna 142 canreceive incident radio frequency radiation. Varying electrical signalson the leads of the energy harvesting antenna 142 are output to therectifier/regulator 146. The rectifier/regulator 146 rectifies thevarying electrical signals to a DC voltage and regulates the rectifiedDC voltage to a level suitable for operating circuitry 150. Additionallyor alternatively, output voltage from the photovoltaic cell(s) 144 canbe regulated to a level suitable for operating the circuitry 150. Therectifier/regulator 146 can include one or more energy storage devicesto mitigate high frequency variations in the energy harvesting antenna142 and/or photovoltaic cell(s) 144. For example, one or more energystorage devices (e.g., capacitors, inductors, etc.) can be connectedwith the outputs of the rectifier/regulator 146 to regulate the DCsupply voltage 148 and/or configured to function as a low-pass filter.

The circuitry 150 is activated when the DC supply voltage 148 isprovided to the circuitry 150, and the logic in the circuitry 150operates the communication electronics 170 to interact with externalreader 190. In some embodiments, the logic in circuitry 150 alsooperates sensor 178 to obtain a reading of the sensor 178. The circuitry150 can include logic circuitry configured to receive modulationinstructions and control light source 176 to provide modulated emittedlight 186 based on the modulation instructions. Additionally oralternatively, the circuitry 150 may be configured to receive themodulation instructions through interaction with the photodetector 172,antenna 174 and/or sensor 178.

In one example, the circuitry 150 includes a photodetector interface 152that is configured to operate photodetector 172 that may be included inthe communication electronics 170. The photodetector 172 can be, forexample, an active pixel sensor (APS), charge-coupled device (CCD),cryogenic detector, photodiode, photoresistor, phototransistor, camera,or any other sensor of light configured to provide a signal throughinterconnects 162 indicative of incident light 182 on the body-mountabledevice 110. The incident light 182 may be visible light or invisiblelight (ultraviolet, infrared, etc.). The incident light 182 detected bythe photodetector 172 may be indicative of a message or of themodulation instructions for the light source 176 included in thebody-mountable device 110. For example, the circuitry 150 may modulatelight emitted by light source 176 based on the message. In otherexamples, the circuitry 150 may control components included in thesubstrate 130 based on the message.

In some instances, the circuitry 150 may include an antenna interface154 that is configured to operate antenna 174 included in thecommunication electronics 170 to send and/or receive information viaantenna 174. The antenna interface 154 can optionally include one ormore oscillators, mixers, frequency injectors, etc. to modulate and/ordemodulate information on a carrier frequency to be transmitted and/orreceived by the antenna 174. In some examples, the body-mountable device110 is configured to indicate an output from sensor 178 by modulating animpedance of the antenna 174 in a manner that is perceivable by theexternal reader 190. For example, the antenna interface 154 can causevariations in the amplitude, phase, and/or frequency of radio frequencyradiation (RF radiation) 184 from the antenna 174, and such variationscan be detected by the reader 190. RF radiation 184 may also includeradiation from the reader 190 to the antenna 174. In some examples, thebody-mountable device 110 is configured to receive RF radiation 184 fromthe reader 190 that is indicative of a message or of the modulationinstructions for the light source 176. For example, circuitry 150 maymodulate light emitted by light source 176 based on the message. Inother examples, the circuitry 150 may control components included in thesubstrate 130 based on the message. The antenna interface 154 can beconnected to antenna 174 via interconnects 164.

The circuitry 150 can also include a modulation interface 156 formodulating light emitted by light source 176. The light emitted by lightsource 176 could be visible light or invisible light (ultraviolet,infrared, etc.). The circuitry 150 can include logic elements and/orcontrollers implemented in an integrated circuit to form the modulationinterface 156. For example, the modulation interface 156 can modify anaspect of the emitted light 186 by light source 176 like color,brightness, intensity, or duration of the emitted light to providemodulated light. The light source 176 may include one or more lightemitting diodes (LED), vertical cavity surface emitting lasers (VCSEL),organic light emitting diodes (OLED), liquid crystal displays (LCD),microelectromechanical systems (MEMS), or any other device configured toselectively transmit, reflect, and/or emit light according toinformation from the modulation interface 156 via the interconnects 166to provide the modulated emitted light 186. In some examples, themodulation interface 156 can include one or more data lines providingprogramming information to separately programmed pixels in the lightsource 176. In some examples, the light source 176 may also include oneor more optical elements to direct the emitted light 186 through thesurface opposite the mounting surface of the transparent material 120.In examples where the body-mountable device 110 is an eye-mountabledevice, the light source 176 disposed on the substrate 130 can beconfigured to emit light through the convex surface (e.g., surfaceopposite the mounting surface) of the transparent material 120 and awayfrom a corneal surface of an eye when the concave surface (e.g., themounting surface) of the transparent material 120 is mounted on thecorneal surface of the eye.

The circuitry 150 can optionally include a sensor interface 158 foroperating a sensor 178. The sensor 178 can be, for example, a bio-sensorconfigured to measure an analyte in a tear film. For example, the sensor178 can be a glucose sensor configured to provide a reading relating toglucose level in the tear film. In some examples, the sensor 178 maymeasure other biological information like blood pressure, temperature,heart rate or psychological state of the user of the body-mountabledevice 110. For example, the sensor 178 can be configured to measure afrequency of eye-blinks to determine the psychological state of theuser. In another example, the sensor 178 can be configured to measurethe concentration of an analyte in saliva (e.g., where thebody-mountable device 110 is a tooth-mounted device). In some examples,the sensor 178 may measure aspects of a surrounding environment of theuser. For example, the sensor 178 may measure the ambient lightintensity or humidity of the surrounding environment. In some examples,the received modulation instructions may be based on the reading of thesensor. For example, the circuitry 150 may be configured to modulate theintensity of the emitted light 186 by the light source 176 according tothe intensity of ambient light indicated by the reading of the sensor178. In other examples, the modulated emitted light 186 may beindicative of the reading of the sensor (e.g., red color may indicatehigh glucose level, blue color may indicate low glucose level, etc.).

The circuitry 150 is connected to the communication electronics 170 viainterconnects 162 and 164. For example, where the circuitry 150 includeslogic elements implemented in an integrated circuit to form thephotodetector 172 and/or the antenna 174, a patterned conductivematerial (e.g., gold, platinum, palladium, titanium, copper, aluminum,silver, metals, combinations of these, etc.) can connect a terminal onthe chip to communication electronics 170. Similarly, the circuitry 150can be connected to the light source 176 via interconnects 166. In someembodiments, the circuitry 150 can be similarly connected to the sensor178 via interconnects 168.

It is noted that the block diagram shown in FIG. 1 is described inconnection with functional modules for convenience in description.However, embodiments of the body-mountable device 110 can be arrangedwith one or more of the functional modules (“subsystems”) implemented ina single chip, integrated circuit, and/or physical component. Forexample, while the rectifier/regulator 146 is illustrated in the powersupply block 140, the rectifier/regulator 146 can be implemented in achip that also includes the logic elements of circuitry 150 and/or otherfeatures of the embedded electronics in the body-mountable device 110.Thus, the DC supply voltage 148 that is provided to the circuitry 150from the power supply 140 can be a supply voltage that is provided tocomponents on a chip by rectifier and/or regulator 146 componentslocated on a same chip. That is, the functional blocks in FIG. 1 shownas the power supply block 140 and circuitry block 150 need not beimplemented as physically separated modules. Moreover, one or more ofthe functional modules described in FIG. 1 can be implemented byseparately packaged chips electrically connected to one another.

Additionally or alternatively, the energy harvesting antenna 142 and theantenna 170 can be implemented with the same physical antenna. Forexample, a loop antenna can both harvest incident radiation for powergeneration and communicate information via backscatter radiation.

The external reader 190 can be a smart phone, digital assistant,head-mounted computing device (e.g., eye glasses with computingcapability), or other computing device with wireless connectivitysufficient to provide the RF radiation 184 and/or the incident light182. The external reader 190 can also be implemented as an antennamodule and/or light source module that can be plugged in to a computingdevice, such as in an example where the RF radiation 184 operates atcarrier frequencies not commonly employed in computing devices, or in anexample where the computing device does not include a light source. Theexternal reader 190 can also be configured to receive the emitted light186 from the body-mountable device 110 via a reader photodetector 196.In some instances, the external reader 190 is a special-purpose deviceconfigured to be worn relatively near a wearer's body to allowcommunication via the RF radiation 184 and/or the incident light 182 tooperate with a low power budget. For example, the external reader 190can be integrated in a piece of jewelry such as a necklace, earing, etc.or integrated in an article of clothing worn near the head, such as ahat, headband, eyeglasses, etc.

In an example where the body-mountable device 110 includes thephotodetector 172, the external reader 190 may include a reader lightsource 192 configured to provide modulated incident light 182 to theeye-mountable device 110. For example, the modulated incident light 182may indicate the received modulation instructions to the circuitry 150such that the circuitry 150 modulates the emitted light 186 based on thereceived modulation instructions. In another example, the modulatedincident light 182 may include instructions to the body-mountable device110 to obtain a reading of the sensor 178. Thus, in this example, thecircuitry 150 may be configured to modulate the emitted light 186 toprovide modulated light indicative of the reading of the sensor. In someexamples, the reader 190 can include the reader photodetector 196 toreceive the modulated emitted light 186 and determine the reading of thesensor based on the modulated emitted light 186. In some examples, themodulated incident light 182 may be indicative of a status of the reader190 or components included in the reader 190. In other examples, themodulated emitted light 186 may be indicative of a status of thebody-mountable device 110 or a status of components included in thebody-mountable device 110. For example, the status of photovoltaiccell(s) 144 may be indicated by the modulated emitted light 186. In someexamples, the external reader 190 can provide light to the photovoltaiccell(s) 144 included in the body-mountable device 110 that areconfigured to harvest the light to provide power to the body-mountabledevice 110.

In an example where the body-mountable device 110 includes an antenna174, the external reader 190 may include a reader antenna 194 configuredto send and/or receive information from the body-mountable device 110via the RF radiation 184. For example, the antenna 174 may be configuredto send information pertaining to the reading of the sensor 178 throughRF radiation 184. Thus, the RF radiation 184 may be received by thereader antenna 194 and the reading of the sensor 178 may be determinedby the reader 190 based on the RF radiation 184. In some examples, thereader antenna 194 may transmit information to the body-mountable device110 via the RF radiation 184. In some examples, the external reader 190may provide the RF radiation 184 to the energy harvesting antenna 142included in the body-mountable device 110 that is configured to harvestthe RF radiation 184 to provide power to the body-mountable device 110.

The external reader 190 can include a processor 198 configured tocontrol reader light source 192, reader antenna 194, and readerphotodetector 196 to perform the functions described in the examplesincluded in the present disclosure. For example, the processor 198 maybe configured to modulate light from the reader light source 192 toprovide the modulated incident light 182.

In some embodiments, the system 100 can operate to non-continuously(“intermittently”) supply energy to the body-mountable device 110 tooperate the power supply 140. For example, incident light 182 and/or RFradiation 184 can be supplied to power the eye-mountable device 110 longenough to obtain a reading by the sensor 178 and wirelessly communicatethe reading via emitted light 186 and/or RF radiation 184 to theexternal reader 190. In such an example, the incident light 182 and/orthe RF radiation 184 can be considered an interrogation signal from theexternal reader 190 to the body-mountable device 110 to request areading. By periodically interrogating the body-mountable device 110(e.g., by supplying the incident light 182 and/or RF radiation 184 totemporarily turn the device on), the external reader 190 can accumulatea series of readings without continuously powering the body-mountabledevice 110.

FIG. 2A is a bottom view of an example eye-mountable device 210(“body-mountable device”). FIG. 2B is a side view of the exampleeye-mountable device 210 shown in FIG. 2A. It is noted that the relativedimensions in FIGS. 2A and 2B are not necessarily to scale, but havebeen rendered for purposes of explanation only in describing thearrangement of the example eye-mountable device 210. The eye-mountabledevice 210 can be formed of a transparent material 220 shaped as acurved disk. The transparent material 220 can allow incident light(e.g., field of view of the eye) to be transmitted to the eye while theeye-mountable device 210 is mounted to the eye. In some examples, thetransparent material 220 can be a biocompatible polymeric materialsimilar to those employed to form vision correction and/or cosmeticcontact lenses in optometry, such as polyethylene terephthalate (PET),polymethyl methacrylate (PMMA), polyhydroxyethylmethacrylate (polyHEMA),silicone hydrogels, combinations of these, etc. The transparent material220 can be formed with one side having a concave surface 226 (e.g.,“mounting surface”, bottom-view surface shown in FIG. 2A, etc.) suitableto fit over a corneal surface of the eye. The opposite side of the diskcan have a convex surface 224 (“surface opposite the mounting surface”)that does not interfere with eyelid motion while the eye-mountabledevice 210 is mounted to the eye. A circular outer side edge 228 canconnect the concave surface 224 and the convex surface 226.

The eye-mountable device 210 can have dimensions similar to a visioncorrection and/or cosmetic contact lenses, such as a diameter ofapproximately 1 centimeter, and a thickness of about 0.1 to about 0.5millimeters. However, the diameter and thickness values are provided forexplanatory purposes only. In some embodiments, the dimensions of theeye-mountable device 210 can be selected according to the size and/orshape of the corneal surface of the wearer's eye.

The transparent material 220 can be formed with a curved shape in avariety of ways. For example, techniques similar to those employed toform vision-correction contact lenses, such as heat molding, injectionmolding, spin casting, etc. can be employed to form the transparentmaterial 220. When the eye-mountable device 210 is mounted to an eye,the convex surface 224 faces outward to an ambient environment while theconcave surface 226 faces inward, toward the corneal surface. The convexsurface 224 can therefore be considered an outer, top surface of theeye-mountable device 210 whereas the concave surface 226 can beconsidered an inner, bottom surface. The “bottom” view shown in FIG. 2Ais facing the concave surface 226.

A substrate 230 is embedded in the transparent material 220. In someexamples, the substrate 230 can be embedded to be along an outerperiphery of the transparent material 220, away from a central region ofthe eye-mountable device 210. Thus, in this example, the substrate 230does not interfere with vision because it is too close to the eye to bein focus and is positioned away from the central region where ambientlight is transmitted to eye-sensing portions of the eye. In someexamples, the substrate 230 can be formed of a transparent material tofurther mitigate effects on visual perception.

The substrate 230 can be shaped as a flat, circular ring (e.g., a diskwith a centered hole). The flat surface of the substrate 230 (e.g.,along the radial width) is a platform for mounting electronics such aschips (e.g., via flip-chip mounting) and for patterning conductivematerials (e.g., via microfabrication techniques such asphotolithography, deposition, plating, etc.) to form electrodes,antenna(e), and/or interconnections. In some examples, the substrate 230and the transparent material 220 can be substantially cylindricallysymmetric about a common central axis. The substrate 230 can have, forexample, a diameter of about 10 millimeters, a radial width of about 1millimeter (e.g., an outer radius 1 millimeter greater than an innerradius), and a thickness of about 50 micrometer. However, thesedimensions are provided for example purposes only, and in no way limitthe present disclosure. The substrate 230 can be implemented in avariety of different form factors, similar to the discussion of thesubstrate 130 in connection with FIG. 1 above.

Circuitry 250, a loop antenna 274 and a sensor 278 are disposed on aside of the substrate 230 that is facing the concave surface 226(“bottom side”) of the transparent material 220 as shown in FIG. 2A. Alight source 276 is disposed on an opposite side of the substrate 230that is facing the convex surface 224 of the transparent material 220(“top side”) as shown in FIG. 2B. However, in some embodiments,circuitry 250, the loop antenna 274, the light source 276 and/or thesensor 278 may be disposed on any side of the substrate 230. Forexample, in some embodiments, the circuitry 250 may be disposed in theopposite side (“top side”) of the substrate 230 that is facing theconvex surface 224 of the transparent material 220. In one example, thelight source 276 may be disposed in the side of the substrate 230 thatis facing the concave surface 226 (“bottom side”). In that case, thesubstrate 230 may include a hole through which light emitted by thelight source 276 can reach the convex surface 224 and propagate awayfrom the corneal surface. In some examples, one or more componentsdisposed on the substrate 230 may be disposed on a side of the substrate230 that is facing the circular outer side edge 228 of the transparentmaterial 220.

In some embodiments not illustrated in FIGS. 2A-2B, the substrate 230may include multiple layers for interconnects and other conductivematerial connected to components disposed on the substrate 230. Otherconfigurations of the substrate 230 are contemplated herein and may beobvious to those of ordinary skill in the art. For example, one of themultiple layers may be utilized as “a ground plane” for the componentsto connect to a ground voltage.

The circuitry 250 may comprise a chip including logic elementsconfigured to operate the loop antenna 274, the light source 276 and thesensor 278. The circuitry 250 is electrically coupled to the loopantenna 274 and the sensor 278, respectively, by interconnects 264 and268. Interconnects 266 electrically connect the circuitry 250 with thelight source 276 through the substrate 230. For example, interconnects266 may be arranged in a through hole connecting the side of thesubstrate 230 that is facing the concave surface 226 (“bottom side”) ofthe transparent material 220 to the opposite side of the substrate 230that is facing the convex surface 224 (“top side”) of the transparentmaterial 220. The interconnects 264, 266, 268, and the loop antenna 274can be formed from conductive materials patterned on the substrate 230by a process for patterning such materials, such as deposition,photolithography, etc. The conductive materials patterned on thesubstrate 230 can be, for example, gold, platinum, palladium, titanium,carbon, aluminum, copper, silver, silver-chloride, conductors formedfrom noble materials, metals, combinations of these, etc. The circuitry250 can be configured to receive modulation instructions and configuredto modulate emitted light 286 from the light source 276 based on thereceived modulation instructions.

The loop antenna 274 can be a layer of conductive material patternedalong a flat surface of the substrate to form a flat conductive ring. Insome instances, the loop antenna 274 can be formed without making acomplete loop. For instance, the loop antenna 274 can have a cutout toallow room for the circuitry 250 and the sensor 278, as illustrated inFIG. 2A. However, the loop antenna 274 can also be arranged as acontinuous strip of conductive material that wraps entirely around theflat surface of the substrate 230 one or more times. For example, astrip of conductive material with multiple windings can be patterned ona side of the substrate 230 opposite the circuitry 250 and sensor 278.Thus, in this example, interconnects 264 between the ends of such awound antenna (e.g., antenna leads) can then be passed through thesubstrate 230 to the circuitry 250 similarly to interconnects 266 inFIG. 2B.

The light source 276 may include one or more light emitting diodes(LED), vertical cavity surface emitting lasers (VCSEL), organic lightemitting diodes (OLED), liquid crystal display (LCD),microelectromechanical system (MEMS), or any other device configured toselectively transmit, reflect, and/or emit light according to receivedmodulation instructions by the circuitry 250 via the interconnects 266to provide the modulated emitted light 286. Operation of the lightsource 276 is similar to light source 176 discussed in FIG. 1. The lightsource 276 is configured to provide the emitted light 286 through theconvex surface 224 and away from the corneal surface.

Although illustrated in FIG. 2B that interconnects 266 are connected toone end of the light source 276, some embodiments may include theinterconnects 266 connected to any other part of the light source 276.For example, the interconnects 266 may be arranged underneath the lightsource 276 so that they are not viewable from the “top” side of theeye-mountable device 210 (the side facing the convex surface 224).

The light source 276 may be configured in a rectangular, triangular,circular and/or any shape that is compatible with the flat surface ofthe substrate 230. For example, the light source 276 may have a loopshape similar to the loop antenna 274. The light source 276 may beconfigured to provide the emitted light 286 based on the receivedmodulation instructions by the circuitry 250. For example, the emittedlight 286 may be indicative of a status of the eye-mountable device 210or a status of components included in the eye-mountable device 210. Forexample, the emitted light 286 may be a blinking light that indicatesinsufficient power being provided to the eye-mountable device 210.

The sensor 278 can be disposed on the substrate 230 and configured toprovide a reading to circuitry 250 via interconnects 268. For example,the received modulation instructions may be indicative of the reading ofthe sensor 278. In some examples, the received modulation instructionsmay be a response to radio frequency radiation received by the loopantenna 274 indicative of obtaining the reading from the sensor 278.

FIG. 2C is a side cross-section view of the example eye-mountable deviceshown in FIGS. 2A and 2B while mounted to a corneal surface 20 of an eye10. FIG. 2D is a close-in side cross-section view enhanced to show thesubstrate 230 embedded in the transparent material 220, the light source276, and the emitted light 286 in the example eye-mountable device 210when mounted as shown in FIG. 2C. It is noted that relative dimensionsin FIGS. 2C and 2D are not necessarily to scale, but have been renderedfor purposes of explanation only in describing the arrangement of theexample eye-mountable device 210. Some aspects are exaggerated to allowfor illustration and facilitate explanation. It is further noted thatthe orientation of the substrate 230 embedded in the transparentmaterial 220 is not necessarily as shown in FIG. 2D. In someembodiments, the substrate 230 may be oriented at any angle such that anoutward-facing flat mounting surface 234 of the substrate 230 is facingthe convex surface 224 of the transparent material 220 and aninward-facing flat mounting surface 232 of the substrate 230 is facingthe concave surface 226 of the transparent material 220.

The eye 10 includes a corneal surface 20 that is covered by bringing anupper eyelid 30 and a lower eyelid 32 together over eye 10. Ambientlight is received by the eye 10 through the corneal surface 20, wherethe ambient light is optically directed to light sensing elements of theeye 10 (e.g., rods and cones, etc.) to stimulate visual perception. Asillustrated in FIG. 2C, the concave surface 226 is configured to beremovably mounted to the corneal surface 20. Additionally, the convexsurface 224 is compatible with motion of the eyelids 30 and 32.

As illustrated in FIG. 2D, the emitted light 286 from the light source276 is directed away from the corneal surface 20 and through the convexsurface 224 when the concave surface 226 is mounted on the cornealsurface 20. For example, the light source 276 can be disposed on theoutward-facing flat mounting surface 234 of the substrate 230 to allowthe emitted light 286 to travel through the convex surface 224. In theexample, interconnects 266 connect the circuitry 250, disposed on theinward-facing flat mounting surface 232 of the substrate 230, to thelight source 276 through the substrate 230.

As shown in the cross-sectional views in FIGS. 2C and 2D, the substrate230 can be inclined such that the flat mounting surfaces 232 and 234 areapproximately parallel to an adjacent portion of the concave surface226. However, in some embodiments, the substrate 230 can be oriented atany angle such that the outward-facing mounting surface 234 is facingthe convex surface 224. As described above, the substrate 230 can be aflattened ring with the inward-facing surface 232 (closer to the concavesurface 226 of the transparent material 220) and the outward-facingsurface 234 (closer to the convex surface 224). The substrate 230 canhave electronic components and/or patterned conductive materials mountedto either or both mounting surfaces 232, 234 or through the substrate230 to connect components from one surface to another.

FIG. 3 is a block diagram of an example method for operating abody-mountable device, in accordance with at least some embodimentsdescribed herein. Method 300 shown in FIG. 3 presents an embodiment of amethod that could be used with the devices 110, and 210, for example.Method 300 may include one or more operations, functions, or actions asillustrated by one or more of blocks 302-306. Although the blocks areillustrated in a sequential order, these blocks may in some instances beperformed in parallel, and/or in a different order than those describedherein. Also, the various blocks may be combined into fewer blocks,divided into additional blocks, and/or removed based upon the desiredimplementation.

In addition, for the method 300 and other processes and methodsdisclosed herein, the flowchart shows functionality and operation of onepossible implementation of present embodiments. In this regard, eachblock may represent a module, a segment, or a portion of a manufacturingor operation process.

At block 302, the method 300 includes receiving modulation instructionsin a body-mountable device that includes a light source and atransparent material, wherein the transparent material has a mountingsurface and a surface opposite the mounting surface.

In some examples, the received modulation instructions can be generatedby circuitry included in the body-mountable device. In one example, thecircuitry can generate the modulation instructions based on a status ofthe body-mountable device (e.g., low power available, malfunctioningcomponent, etc.). In another example, the circuitry can generate themodulation instructions based on a reading of a sensor included in thebody-mountable device (e.g., a high glucose reading of a glucosesensor). In another example, the circuitry can generate the modulationinstructions based on data and/or instructions received from an externaldevice (e.g., a reader, a computing device, etc.). For example, the datacan indicate a time of day, and the circuitry can generate themodulation instructions to modulate the light to a color suitable forthe time of day (e.g., green at morning, blue at midday, red at night,etc.).

Additionally or alternatively, in some examples, the body-mountabledevice can receive the modulation instructions from an external device(e.g., head-mounted device, mobile phone, computing device, etc.). Forexample, the external device can send the modulation instructionsindicative of modulating the light to a certain color or brightness(e.g., for aesthetic purposes). In some examples, the external devicecan send the modulation instructions via radio frequency radiation (RFradiation), and the body-mountable device can include an antennaconfigured to receive the RF radiation. In some examples, the externaldevice can send the modulation instructions via an incident light signalfrom a light source included in the external device, and thebody-mountable device can include a photodetector configured to receivethe incident light signal.

At block 304, the method 300 includes modulating, based on themodulation instructions, light emitted by the light source to providemodulated light.

At block 306, the method 300 includes emitting the modulated lightthrough the surface opposite the mounting surface, wherein the modulatedlight is indicative of a human-discernible or machine readable messagefrom the body-mountable device.

For example, the body-mountable device may include a sensor configuredto provide a measurement of an analyte in a tear film of an eye (e.g.,glucose) when the body-mountable device is mounted on the eye. Thus, themethod 300 could include generating and/or receiving the modulationinstructions based on the reading of the sensor (step 302), modulatingthe light emitted (step 304) by the light source (e.g., red color forhigh reading, green color for normal reading, blue color for lowreading), and emitting the modulated light (step 306) through the convexsurface (e.g., surface opposite the mounting surface) and away from theeye (similarly to the emitted light 286 in the embodiment illustrated inFIG. 2D). In some examples, the modulated light can be indicative of amessage from the body-mountable device. In some examples, the messagemay relate to a status of the body-mountable device (e.g., low powerremaining)

Although not illustrated in FIG. 3, in some examples, the body-mountabledevice may include a photodetector. The method 300 may receive themodulation instructions based on incident light on the photodetector.For example, a hand-held mobile device may emit infrared light towardsthe body-mountable device that corresponds to the modulationinstructions. In such an example, the infrared light may relate tochanging the color of the light emitted by the body-mountable device(e.g., for aesthetic purposes). The body-mountable device may thenmodify the color of the emitted light based on the received modulationinstructions.

FIG. 4 is a block diagram of an example method for operating abody-mountable device via an antenna, in accordance with at least someembodiments described herein. Method 400 shown in FIG. 4 presents anembodiment of a method that could be used with the devices 110, and 210,for example. Method 400 may include one or more operations, functions,or actions as illustrated by one or more of blocks 402-408. Although theblocks are illustrated in a sequential order, these blocks may in someinstances be performed in parallel, and/or in a different order thanthose described herein. Also, the various blocks may be combined intofewer blocks, divided into additional blocks, and/or removed based uponthe desired implementation.

In addition, for the method 400 and other processes and methodsdisclosed herein, the flowchart shows functionality and operation of onepossible implementation of present embodiments. In this regard, eachblock may represent a module, a segment, or a portion of a manufacturingor operation process.

At block 402, radio frequency radiation is received at an antenna in abody-mountable-device including an embedded outward-facing light source.The body-mountable device has a mounting surface and a surface oppositethe mounting surface. The eye-mountable device further comprises asensor.

At block 404, the body-mountable device obtains a reading of the sensorin response to the radio frequency radiation (e.g., the radio frequencyradiation may provide power to the body-mountable device or a request toobtain the reading).

At block 406, the body-mountable device modulates light emitted by thelight source based on the reading of the sensor (e.g., modify color oflight according to the reading).

At block 408, the body-mountable device emits the modulated lightthrough the surface opposite the mounting surface.

In one example, the radio frequency radiation may pertain to modulationinstructions (“message”) for the body-mountable device (step 402). Forexample, the radio frequency radiation may define the modulation oflight according to each sensor reading (e.g., define color for lowreading, define color for high reading, etc.). Thus, in this example,the body-mountable device may then modulate the light emitted by thelight source based on the reading of the sensor and according to themodulation instructions (step 406). The light source may then emit themodulated light through the surface opposite the mounting surface sothat people around a user of the body-mountable device may be alerted bythe sensor measurement about the user of the body-mountable device.

FIG. 5A is a block diagram of an example system 500 with aneye-mountable device 530 (“body-mountable device”) that includes anoutward facing light source and is operated by an external reader 510.The eye-mountable device 530 can be configured to be contact-mountedover a corneal surface of an eye 10. The eye-mountable device 530 can beconfigured to receive modulation instructions from the external reader510, and modulate emitted light 540.

The external reader 510 includes a processor 512 and a memory 514. Theprocessor 512 can be a computing system that executes software stored inthe memory 514 to cause system 500 to operate, as described herein, theeye-mountable device 530. The external reader 510 can also include anantenna (not shown) for transmitting radio frequency radiation 520 (RFradiation) that is received by the eye-mountable device 530. Forexample, the RF radiation 520 may correspond to the received modulationinstructions. The external reader 510 can be configured to provide themodulation instructions to modify an aspect of the emitted light 540(e.g., color, brightness, intensity, duration, etc.).

For instance, the external reader 510 may be a hand-held computingdevice (e.g. mobile phone, personal digital assistant, etc.). In such anexample, a user of system 500 may select the appearance (color,intensity, frequency, etc.) of the emitted light 540 as the user wishes.For example, the user may want to change the aesthetic appearance of theeye-mountable device 530 by selecting brighter light, different color,etc. Thus, the external reader 510 can send modulation instructions tothe eye-mountable device 530 pertaining to the selected modulation bythe user. As a result, the eye-mountable device 530 can modulate theemitted light 540 to reflect the user's selections. In other examples,the modulation instructions may be determined based on instructions inthe memory 514. For example, the modulation instructions may beindicative of an appointment in a calendar of the user determined by theexternal reader 510. For example, the eye-mountable device 530 maymodulate the emitted light 540 (e.g. flashing red light) to indicate topeople around the user that the user has an upcoming appointment.

FIG. 5B is a block diagram of the eye-mountable device 530 described inconnection with FIG. 5A. The eye-mountable device 530 includes theoutward facing light source 532, an antenna 534, and circuitry 536. Theoutward-facing light source 532 provides the emitted light 540 asdescribed in FIG. 5A. The antenna 534 can be configured to receive theRF signal 520 (shown in FIG. 5A) that pertains to the modulationinstructions. Circuitry 536 can be configured to determine themodulation instructions based on the received RF signal 520. Circuitry536 can also be configured to modulate the emitted light 540 bycontrolling the light source 532.

FIG. 6A is a top view of an example eye-mountable device 610(“body-mountable device”). FIG. 6B is a side view of the exampleeye-mountable device 610 shown in FIG. 6A. It is noted that the relativedimensions in FIGS. 6A and 6B are not necessarily to scale, but havebeen rendered for purposes of explanation only in describing thearrangement of the example eye-mountable device 610.

The composition, arrangement, and shape of a transparent material 620,substrate 630, and interconnects 662, 666 included in the eye-mountabledevice 610 is similar to the transparent material 220, substrate 230,and interconnects 264, 266, 268 discussed in device 210. Similarly, thetransparent material 620 can be formed with one side having a concavesurface 626 (“mounting surface”) suitable to fit over a corneal surfaceof an eye. The opposite side of the disk (top-view surface shown in FIG.6A) can have a convex surface 624 (“surface opposite the mountingsurface”) that does not interfere with eyelid motion while theeye-mountable device 210 is mounted to the eye. A circular outer sideedge 628 connects the concave surface 624 and the convex surface 626.The eye-mountable device 610 can have dimensions similar to theeye-mountable device 210 discussed in the description of FIGS. 2A-2D.When the eye-mountable device 610 is mounted to the eye, the convexsurface 624 faces outward to a surrounding environment while the concavesurface 626 faces inward, toward the corneal surface. The convex surface624 can therefore be considered an outer, top surface of theeye-mountable device 610 whereas the concave surface 626 can beconsidered an inner, bottom surface. The “top” view shown in FIG. 6A isfacing the convex surface 624.

Circuitry 650, light source 676, and photodetector 672 are disposed onthe top surface of the substrate 630 (surface that is closer to theconvex surface 624). Interconnects 662 and 666 connect circuitry 650,respectively, with the photodetector 672 and the light source 676.

The photodetector 672 is similar to the photodetector 172 discussed insystem 100. The photodetector 672 may be configured to receive incidentlight that pertains to modulation instructions for the eye-mountabledevice 610. The incident light may be invisible light (infrared,ultraviolet, etc.) or visible light. The photodetector 672 can transmitan electrical signal indicative of the incident light throughinterconnects 662 to the circuitry 650.

Circuitry 650 can be configured to receive the electrical signal fromthe photodetector 672 and determine, based on the electrical signal,modulation instructions for emitted light 686. The circuitry may thenmodulate the emitted light 686 by controlling the light source 676 viainterconnects 666. Additionally or alternatively, the circuitry 650 maycontrol one or more components included in the eye-mountable device 610based on the electrical signal.

The light source 676 is similar to the light source 276 discussed in theeye-mountable device 210 of FIGS. 2A-2D. The light source 676 canprovide the emitted light 686, based on the modulation instructionsreceived from the circuitry.

In some examples, the example eye-mountable device 610 may receiveincident light from an external computing device not shown in FIGS.6A-6B. For example, the external computing device may interrogate theeye-mountable device 610 on a status of the eye-mountable device 610 byconveying a message through the incident light that is received by thephotodetector 672. In one example, the circuitry 650 may determine thatthe eye-mountable device is low on power based on a measurement of thecurrent going through one or more component. Thus, the circuitry 650 canmodulate the emitted light 686 to indicate the status of theeye-mountable device.

In some examples, the photodetector 672 and the light source 676 can beused as a communication means between the eye-mountable device 610 andone or more external computing devices within a line of sight of theeye-mountable device 610 when the eye-mountable device 610 iscontact-mounted on an eye. For example, incident light can pertain to amessage to the eye-mountable device 610 and emitted light 686 canpertain to a message from the eye-mountable device 610.

FIG. 7A is a block diagram of an example system 700 with aneye-mountable device 730 (“body-mountable device”) and an externalreader 710 that are communicating via emitted light 740 by theeye-mountable device 730 and incident light 750 from the external reader710. The eye-mountable device 730 can be configured to becontact-mounted over a corneal surface of an eye 10. The eye-mountabledevice 730 can be configured to receive instructions from the externalreader 710 via the incident light 750, and modulate emitted light 740 tocommunicate, for example, information to the external reader 710.

The external reader 710 includes a processor 712 and a memory 714. Theprocessor 712 can be a computing system that executes software stored inthe memory 714 to cause system 700 to communicate, as described herein,information from the external reader 710 to the eye-mountable device 730via the incident light 750 emitted by a reader light source 718. Forexample, the incident light 750 may correspond to instructions from theexternal reader 710 to the eye-mountable device 730. The external reader710 can be configured to provide the incident light 750 by modifying anaspect of the incident light 750 (e.g., color, brightness, intensity,duration, etc.) emitted by the reader light source 718. The readerphotodetector 716 can be configured to receive the emitted light 740.The reader light source 718 can be configured to provide the incidentlight 750.

FIG. 7B is a block diagram of the eye-mountable device 730 described inconnection with FIG. 7A. The eye-mountable device 730 includes anoutward facing light source 732, a photodetector 734, circuitry 736, anda sensor 738. The outward-facing light source 732 provides the emittedlight 740 as described in FIG. 7A. The photodetector 734 can beconfigured to receive the incident light 750 (shown in FIG. 7A) thatpertains to the communication from the external reader 710 in FIG. 7A.Circuitry 736 can be configured to determine modulation instructions forthe light source 732 based on the received incident light 750. Circuitry736 can also be configured to modulate the emitted light 740 bycontrolling the light source 732 to communicate information to theexternal reader 710. The light source 732 can be configured to providethe emitted light 740 by modifying an aspect of the emitted light 740(e.g., color, brightness, intensity, duration, etc.). Sensor 738 can bea sensor embedded in the eye-mountable device 730 and configured toprovide a reading to the circuitry 736. For example, the circuitry 736can be configured to obtain the reading from the sensor 738 andcommunicate the reading to the reader 710 in FIG. 7A by modulating theemitted light 740 from the light source 732.

System 700 can be configured to communicate information between theexternal reader 710 and the eye-mountable device 730, respectively, viathe incident light 750 and the emitted light 740. For example, where theexternal reader 710 is a computing device in a field of view of theeye-mountable device 730 (e.g., head-mounted device, wearable device,hand-held device, desktop computer, etc.), some example communicationscenarios are described below.

In a first example, the external reader 710 can be configured tointerrogate the eye-mountable device 730 by modulating the incidentlight 750 from the reader light source 718. The circuitry 736 includedin the eye-mountable device 730 can be configured to receiveinstructions from the external reader 710 based on the incident light750 received via the photodetector 734. For example, the circuitry 736can be configured to obtain a reading from the sensor 738 based on thereceived instructions. The sensor 738 can be configured to provide tothe circuitry 736 the reading indicating biological vitals (e.g., bloodpressure, heart rate, temperature, glucose level, psychological state,etc.) of a user of the eye-mountable device 730. The circuitry 736 canbe configured to modulate the emitted light 740 from the light source732 to indicate the reading of the sensor 738. The external reader 710can receive the emitted light 740 via the reader photodetector 716 anddisplay the biological vitals to the user via a display included in thereader (not shown in FIG. 7A).

In a second example similar to the first example, the reading of thesensor 738 may relate to an ambient environment of the user. Forexample, the reading may indicate humidity, temperature, ambient lightintensity, etc. The external reader 710 can be configured to displayinformation relating to the ambient environment to the user.

In a third example, the emitted light 740 from the eye-mountable device730 can be used by the external reader 710 to determine a line of sight(LOS) of the user of the eye-mountable device. For example, where theexternal reader 710 includes a display (e.g., head mounted display) notshown in FIG. 7A, the external reader 710 can determine the line ofsight of the user looking at the display. Thus, in this example, theexternal reader 710 can determine what portion of the display the useris looking at.

In a fourth example, the emitted light 740 from the eye-mountable device730 can be indicative of a status of the eye-mountable device 730. Forexample, the emitted light 740 can indicate if one or more components ofthe eye-mountable device 730 are malfunctioning (e.g., consuming morepower than expected).

FIG. 8 is a block diagram of an example method 800 for operating anexternal reader to receive an incident signal transmitted by abody-mountable device, in accordance with at least some embodimentsdescribed herein. Method 800 shown in FIG. 8 presents an embodiment of amethod that could be used with the devices 190, 510, and 710, forexample. Method 800 may include one or more operations, functions, oractions as illustrated by one or more of blocks 802-804. Although theblocks are illustrated in a sequential order, these blocks may in someinstances be performed in parallel, and/or in a different order thanthose described herein. Also, the various blocks may be combined intofewer blocks, divided into additional blocks, and/or removed based uponthe desired implementation.

In addition, for the method 800 and other processes and methodsdisclosed herein, the flowchart shows functionality and operation of onepossible implementation of present embodiments. In this regard, eachblock may represent a module, a segment, or a portion of a manufacturingor operation process.

At block 802, the method 800 includes receiving, by a reader device, anincident signal transmitted by a body-mountable device, wherein theincident signal comprises light emitted by a light source included inthe body-mountable device.

At block 804, the method 800 includes determining, based on the incidentsignal, a message from the body-mountable device.

For example, the body-mountable device may send modulated light(“incident signal”) towards the external reader indicative of a statusof the body-mountable device (step 802). For example, the body-mountabledevice may be low on power and the modulated light may indicate to theexternal reader that the body-mountable device is low on power. Thereader device may determine the message (e.g., low power) based on themodulated light (“incident signal”) (step 804). Although not illustratedin FIG. 8, in some examples, the body-mountable device may include aphotodetector to receive incident light (“incident signal”). The method800 may determine the message based on the incident light on thephotodetector.

FIG. 9 is a block diagram of an example method 900 for operating anexternal reader to communicate, via light, with a body-mountable device,in accordance with at least some embodiments described herein. Method900 shown in FIG. 9 presents an embodiment of a method that could beused with the devices 190, 510, and 710, for example. Method 900 mayinclude one or more operations, functions, or actions as illustrated byone or more of blocks 902-908. Although the blocks are illustrated in asequential order, these blocks may in some instances be performed inparallel, and/or in a different order than those described herein. Also,the various blocks may be combined into fewer blocks, divided intoadditional blocks, and/or removed based upon the desired implementation.

In addition, for the method 900 and other processes and methodsdisclosed herein, the flowchart shows functionality and operation of onepossible implementation of present embodiments. In this regard, eachblock may represent a module, a segment, or a portion of a manufacturingor operation process.

At block 902, a reader device receives emitted light from abody-mountable device using a photodetector included in the readingdevice.

At block 904, the reader device determines, based on the emitted light,a message from the body-mountable device.

At block 906, the reader device determines a response to the message.

At block 908, the reader device transmits modulated light to thebody-mountable device, wherein the modulated light is indicative ofinstructions and data pertaining to the response, wherein thebody-mountable device is configured to receive the modulated light.

For example, the reader device can be a portable computing device (e.g.,laptop, hand held device, etc.) configured to receive emitted light fromthe body-mountable device using the photodetector included in theportable computing device (step 902). The reader device can determinefrom the emitted light that a status of the body-mountable device isidle (step 904). The reader device may then determine a response to themessage (step 906) indicative of instructions to modify the emittedlight by the body-mountable device to a green color to indicate thestatus of the device. The reader device may transmit the response (step908) by providing modulated light to the body-mountable device that isconfigured to receive the modulated light such that the body-mountabledevice emits the green color.

FIG. 10 depicts an example computer-readable medium configured accordingto at least some embodiments described herein. In example embodiments,the example system can include one or more processors, one or more formsof memory, one or more input devices/interfaces, one or more outputdevices/interfaces, and machine readable instructions that when executedby the one or more processors cause the system to carry out the variousfunctions tasks, capabilities, etc., described above.

As noted above, in some embodiments, the disclosed techniques (e.g.methods 300, 400, 800, and 900) can be implemented by computer programinstructions encoded on a non-transitory computer readable storage mediain a machine-readable format, or on other non-transitory media orarticles of manufacture (e.g., the instructions stored on the memorystorage 514 of the reader 510 of the system 500). FIG. 10 is a schematicillustrating a conceptual partial view of an example computer programproduct that includes a computer program for executing a computerprocess on a computing device, arranged according to at least someembodiments disclosed herein.

In one embodiment, the example computer program product 1000 is providedusing a signal bearing medium 1002. The signal bearing medium 1002 mayinclude one or more programming instructions 1004 that, when executed byone or more processors may provide functionality or portions of thefunctionality described above with respect to FIGS. 1-9. In someexamples, the signal bearing medium 1002 can be a non-transitorycomputer-readable medium 1006, such as, but not limited to, a hard diskdrive, a Compact Disc (CD), a Digital Video Disk (DVD), a digital tape,memory, etc. In some implementations, the signal bearing medium 1002 canbe a computer recordable medium 1008, such as, but not limited to,memory, read/write (R/W) CDs, R/W DVDs, etc. In some implementations,the signal bearing medium 1002 can be a communication medium 1010 (e.g.,a fiber optic cable, a waveguide, a wired communications link, awireless communication link, etc.). Thus, for example, the signalbearing medium 1002 can be conveyed by a wireless form of thecommunications medium 1010.

The one or more programming instructions 1004 can be, for example,computer executable and/or logic implemented instructions. In someexamples, a computing device such as the processor-equipped externalreader 190 of FIG. 1 is configured to provide various operations,functions, or actions in response to the programming instructions 1004conveyed to the computing device by one or more of the computer readablemedium 1006, the computer recordable medium 1008, and/or thecommunications medium 1010.

The non-transitory computer readable medium 1006 can also be distributedamong multiple data storage elements, which could be remotely locatedfrom each other. The computing device that executes some or all of thestored instructions could be an external reader such as the reader 190illustrated in FIG. 1, or another mobile computing platform, such as asmartphone, tablet device, personal computer, head-mounted device, etc.Alternatively, the computing device that executes some or all of thestored instructions could be remotely located computer system, such as aserver. For example, the computer program product 1000 can implement thefunctionalities discussed in the description of FIGS. 1-9.

Within examples, operation methods that are described for the device canbe applied to other electronic devices that include an outward-facinglight source. For example, implantable devices that measure biologicalinformation can include a light source directed outwards from a bodywhere the implantable devices are implanted. Thus, example methodsherein provide operation methods that involve an outward-facing lightsource, receiving modulation instructions, and modulating light emittedby the outward-facing light source based on the modulation instructions.

It should be understood that arrangements described herein are forpurposes of example only. As such, those skilled in the art willappreciate that other arrangements and other elements (e.g. machines,interfaces, functions, orders, and groupings of functions, etc.) can beused instead, and some elements may be omitted altogether according tothe desired results. Further, many of the elements that are describedare functional entities that may be implemented as discrete ordistributed components or in conjunction with other components, in anysuitable combination and location, or other structural elementsdescribed as independent structures may be combined.

Where example embodiments involve information related to a person or adevice of a person, some embodiments may include privacy controls. Suchprivacy controls may include, at least, anonymization of deviceidentifiers, transparency and user controls, including functionalitythat would enable users to modify or delete information relating to theuser's use of a product.

Further, in situations in where embodiments discussed herein collectpersonal information about users, or may make use of personalinformation, the users may be provided with an opportunity to controlwhether programs or features collect user information (e.g., informationabout a user's medical history, social network, social actions oractivities, profession, a user's preferences, or a user's currentlocation) and an opportunity to control whether or how personalinformation is used. In addition, certain data may be treated in one ormore ways before it is stored or used, so that personally identifiableinformation is removed. For example, a user's identity may be treated sothat no personally identifiable information can be determined for theuser, or a user's geographic location may be generalized where locationinformation is obtained (such as to a city, ZIP code, or state level),so that a particular location of a user cannot be determined. Thus, theuser may have control over how information is collected about the userand how the collected information is used.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting, with the true scopebeing indicated by the following claims, along with the full scope ofequivalents to which such claims are entitled. It is also to beunderstood that the terminology used herein is for the purpose ofdescribing particular embodiments only, and is not intended to belimiting.

What is claimed is:
 1. A reader device comprising: a first light source;a first photodetector; a processor; and a memory storing programinstructions, wherein the program instructions are executable by theprocessor to cause the reader device to perform operations comprising:communicating with a body-mountable device via at least one of the firstlight source or first photodetector, wherein the body-mountable devicecomprises a second light source and a second photodetector.
 2. Thereader device of claim 1, wherein communicating with the body-mountabledevice via at least one of the first light source or first photodetectorcomprises: emitting light from the first light source, wherein the lightemitted from the first light source is indicative of an instruction fromthe reader device to the body-mountable device.
 3. The reader device ofclaim 2, wherein communicating with the body-mountable device via atleast one of the first light source or first photodetector furthercomprises: receiving, by the first photodetector, light emitted by thesecond light source of the body-mountable device, wherein the lightemitted by the second light source of the body-mountable device isindicative of a reading obtained by a sensor in the body-mountabledevice.
 4. The reader device of claim 3, wherein the reading obtained bythe sensor is indicative of a glucose level.
 5. The reader device ofclaim 2, wherein communicating with the body-mountable device via atleast one of the first light source or first photodetector furthercomprises: receiving, by the first photodetector, light emitted by thesecond light source of the body-mountable device, wherein the lightemitted by the second light source of the body-mountable device isindicative of a status of the body-mountable device.
 6. The readerdevice of claim 1, wherein communicating with the body-mountable devicevia at least one of the first light source or first photodetectorcomprises: receiving, by the first photodetector, light emitted by thesecond light source of the body-mountable device.
 7. The reader deviceof claim 6, wherein communicating with the body-mountable device via atleast one of the first light source or first photodetector furthercomprises: determining a message from the body-mountable device based onthe light emitted by the second light source of the body-mountabledevice.
 8. The reader device of claim 7, wherein the message relates toa reading obtained by a sensor in the body-mountable device.
 9. Thereader device of claim 7, wherein the message relates to a status of thebody-mountable device.
 10. The reader device of claim 7, whereincommunicating with the body-mountable device via at least one of thefirst light source or first photodetector further comprises: determininga response to the message.
 11. The reader device of claim 10, whereincommunicating with the body-mountable device via at least one of thefirst light source or first photodetector further comprises:transmitting light from the first light source to the body-mountabledevice, wherein the light transmitted from the first light source isindicative of the response.
 12. The reader device of claim 1, whereinthe body-mountable device is an eye-mountable device.
 13. The readerdevice of claim 1, wherein the reader device is a wearable computingdevice or hand-held computing device.
 14. A non-transitory computerreadable medium having stored therein program instructions executable bya processor of a reader device to cause the reader device to performoperations, the reader device comprising a first light source and afirst photodetector, the operations comprising: communicating with abody-mountable device via at least one of the first light source or thefirst photodetector, wherein the body-mountable device comprises asecond light source and a second photodetector.
 15. The non-transitorycomputer readable medium of claim 14, wherein communicating with thebody-mountable device via at least one of the first light source or thefirst photodetector comprises: emitting light from the first lightsource, wherein the light emitted from the first light source isindicative of an instruction from the reader device to thebody-mountable device.
 16. The non-transitory computer readable mediumof claim 14, wherein communicating with the body-mountable device via atleast one of the first light source or the first photodetectorcomprises: receiving, by the first photodetector, light emitted by thesecond light source of the body-mountable device, wherein the lightemitted by the second light source of the body-mountable device isindicative of at least one of a status of the body-mountable device or areading obtained by a sensor in the body-mountable device.
 17. A method,comprising: communicating, by a reader device, with a body-mountabledevice, wherein the reader device comprises a first light source and afirst photodetector, wherein the body-mountable device comprises asecond light source and a second photodetector, and wherein thecommunicating involves at least one of the first light source or firstphotodetector.
 18. The method of claim 17, wherein the communicatingcomprises: emitting light from the first light source, wherein the lightemitted from the first light source is indicative of an instruction fromthe reader device to the body-mountable device.
 19. The method of claim17, wherein the communicating comprises: receiving, by the firstphotodetector, light emitted by the second light source of thebody-mountable device, wherein the light emitted by the second lightsource of the body-mountable device is indicative of at least one of astatus of the body-mountable device or a reading obtained by a sensor inthe body-mountable device.